#treeViewLeft .tree-cell .tree-disclosure-node .arrow {
    -fx-shape: null;
    -fx-background-color: null;
    -fx-background-image: url("Triangular10.png");
}
#treeViewLeft .tree-cell:expanded .tree-disclosure-node .arrow {
    -fx-shape: null;
    -fx-background-color: null;
    -fx-background-image: url("Triangular10.png");
}

#treeViewRight .tree-cell .tree-disclosure-node .arrow {
    -fx-shape: null;
    -fx-background-color: null;
    -fx-background-image: url("root.png");
}

#treeViewRight .tree-cell:expanded .tree-disclosure-node .arrow {
    -fx-shape: null;
    -fx-background-color: null;
    -fx-background-image: url("root.png");
}